Research Methods: A Comprehensive Study

Side 1: Chapter 4 – Research Design

Definition

The plan or blueprint for a study, outlining how data will be collected and analyzed.

Types

  • Exploratory
  • Descriptive
  • Causal

Key Research Design Types

Exploratory Research

Conducted when little is known, aims to gain insights and clarify ideas.

Descriptive Research

Provides a detailed description of phenomena, without manipulation.

Causal Research

Establishes cause-and-effect relationships between variables.

Sampling Design

Probability Sampling

Every member of the population

Read More

Key Concepts in Statistics: Data, Methods & Limitations

Limitations of Statistics

  • Statistics does not deal with individuals:
    • Statistics deals with an aggregate of facts and does not give specific recognition to individual items in a series.
    • It deals with groups of individuals and indicates the characteristics of the whole group.
  • Statistics does not deal directly with qualitative characteristics:
    • Statistical methods can only be applied to numerically expressed data.
    • A qualitative phenomenon must be converted into quantitative information before statistical
Read More

Understanding Statistical Variability and Distributions

Understanding Measures of Variability

Measures of variability indicate how much scores in a distribution vary, either from the mean or across the full extent of the distribution. It represents the spread of all the scores. Four measures of variability are discussed here: the range, the average mean deviation, the variance, and the standard deviation. These measures can reveal the consistency or similarity of the scores in a distribution and the extent to which the mean truly represents all of the

Read More

Understanding Disease Frequency: Incidence, Prevalence, and Public Health Measures

Definition of Proportion

  • A measure that states a count relative to the size of the group.
  • A ratio in which the numerator is part of the denominator.
  • May be expressed as a percentage.

Definition of Rate

  • A ratio that consists of a numerator and a denominator and in which time forms part of the denominator.
  • Contains the following elements:
    • Disease frequency
    • Unit size of population
    • Time period during which an event occurs

Example of Rate Calculation

2Q==

Definition of Prevalence

The number of existing cases of a disease

Read More

Core Statistical Concepts and Applications

Linear Regression: Test Scores vs. Hours Studied

Consider the following linear regression equation: Test Scores = 45 + 5(Hours Studied)

  • The Test Scores variable is the outcome variable. It is what the model is trying to predict.
  • Hours Studied is the explanatory variable. It is used to explain or predict changes in the test scores.
  • The slope coefficient associated with Hours Studied is 5. This indicates that for every additional hour spent studying, the model predicts an increase of 5 points in the test
Read More

Statistics Concepts: Observational Studies, Bias, and Inference

Statistics Concepts and Definitions

Ex. 1:

Observational study: No cause-effect; just associations. Five Number Summary = Min, Q1, Median, Q3, Max

Factors: Explanatory variable (x). Covariance: + or – relation but not strength

Block design: Individuals sharing the same characteristic are pooled.

SRS (Simple Random Sample); Stratified: Sample distinct groups separately then combine them. Sample survey: Cross-sectional; collect data of a population at one point in time.

Multistage: Using SRS within SRSs.

Read More